P1300: CLINICAL CHARACTERISTICS AND OUTCOMES OF ALLOGENEIC STEM CELL TRANSPLANTATION RECIPIENTS WITH CORONAVIRUS DISEASE 2019 CAUSED BY THE OMICRON VARIANT: A PROSPECTIVE, OBSERVATIONAL COHORT STUDY
Authors: Shuang Fan, Xiaodong Mo, Xiaohui Zhang, Lanping Xu, Yu Wang, Chenhua Yan, Huan Chen, Yuanyuan Zhang, Yifei Cheng, Yuqian Sun, Yuhong Chen, Yao Chen, Wei Han, Jingzhi Wang, Fengrong Wang, Zhengli Xu, Xiaojun Huang
Journal: HemaSphere (2023)

Topic: 22. Stem cell transplantation - Clinical Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are the most representative immunocompromised patients. COVID-19 infection has an adverse influence on clinical outcomes of allo-HSCT recipients, and disease severity is significantly associated with mortality after COVID-19 infection. Thus, identifying the occurrence and risk factors of severe/critical illness is important to further improve the survival of allo-HSCT recipients infected with COVID-19. However, the sample of allo-HSCT recipients was small and they could not identify the occurrence and rick factors of severe/critical illness in these patients. Thus far, data from large studies in allo-HSCT recipients who infected with Omicron variant are lacking. Aims: In the present study, we aimed to describe the clinical characteristics, particularly the occurrence and rick factors of severe/critical illness, in allo-HSCT recipients infected with Omicron variant, and we also wanted to identify the clinical outcomes (e.g., ICU admission, infection resolution, and survival) of these patients. Methods: We performed an observational prospective study in Peking University, Institute of Hematology (n = 311). The final follow-up visit was on January 22, 2022, and survivors needed to have at least 4 weeks of follow-up after symptoms onset. This work was supported by the National Key Research and Development Program of China (No. 2022YFA1103300, 2022YFC2502606), Major Program of the National Natural Science Foundation of China (No. 82293630), the Key Program of the National Natural Science Foundation of China (No. 81930004), the National Natural Science Foundation of China (No. 82170208), CAMS Innovation Fund for Medical Sciences (No. 2019-I2M-5-034, 2022-I2M-C&T-B-121), and the Fundamental Research Funds for the Central Universities. Results: The median time from allo-HSCT to COVID-19 diagnosis was 8.5 months (range 0.8–106.1) months. Four patients (1.3%) were reported to be asymptomatic during Omicron variant infection, and 135 (43.4%) patients showed lower respiratory tract disease. Thirty-four (10.9%) patients were categorized into serious infection (severe illness, n=25; critical illness: n=9) and the median duration from COVID-19 diagnosis to serious infections was 6 days (range, 0–29) days. Thirteen (4.2%) and 6 (1.9%) patients required intensive care unit care and invasive mechanical ventilation, respectively. Receiving more than 1 type of immunosuppressive therapies at COVID-19 diagnosis was associated with severity and persistence of infection. Six patients (1.9%) died after diagnosis of COVID-19 infection. The 4-week probability of overall survival after COVID-19 diagnosis was 98.7%, which was 100% and 88.2 for non-serious and serious infection group (P < 0.001), respectively. Summary/Conclusion: We observed a relatively low serious infection and mortality rate in allo-HSCT recipients infected with COVID-19 caused by Omicron variant.Keywords: Allogeneic hematopoietic stem cell transplant